What are the names of blue hydrangeas and how many are there? Changing the color of hydrangea

Hydrangeas will produce blue flowers (not pink) if grown in acidic soil. Sometimes hydrangeas can change color over time if the acidity level of the soil changes. Therefore, if you want to constantly have blue flowers, you will need to monitor the pH of the soil and take measures to maintain its acidity. This is quite easy to do - just skip to Step 1 first.

Steps

Part 1

Scientific background

    Know that hydrangeas will produce blue flowers in acidic soil, while pink flowers will appear on hydrangeas in alkaline soil. Hydrangeas can be called unique garden plants

  1. bloom with pink or blue flowers. Check the acidity (pH) of your soil.

    • To find out whether the soil in your garden is alkaline or acidic, determine the pH value. This will help you know how likely your hydrangea is to produce blue flowers.
    • If the soil pH is below 5.5, your hydrangeas will bloom bright blue flowers.
    • If the pH is between 5.5 and 6.5, the flowers will have a fantastic purple color.

  2. If the pH is above 6.5, the flowers will be pink. To determine whether your soil is acidic or alkaline, use white vinegar.

    For this you need distilled white vinegar. Take a handful of soil, pour vinegar on top and wait for the reaction. Determine soil pH using the scientific method. If you want to know pH level of your soil, you can check it using a set of test instruments designed for this purpose. Such kits are widely available at garden centers or online stores. When using them, follow the instructions on the package.

    • Alternatively, you can take a sample of your soil to your local garden center, where they will determine the acidity level (pH) of your soil.

    Part 2

    How to make soil more acidic

    1. Spray the soil with elemental sulfur. To save Blue colour For your hydrangea flowers, spray the soil around the bush with elemental sulfur to reduce the pH below 5.5. The amount of elemental sulfur required will vary depending on the type of soil and how much the pH needs to be adjusted.

      • To lower the pH by one unit in loam or silty clay soils, apply ¾ pound of elemental sulfur per 25 square feet. In other words, it takes ¾ pound to lower the pH from 6 to 5. On sandy or sandy loam soil, it takes less than ¼ pound of elemental sulfur to lower the pH by one.
      • Start spraying the soil with elemental sulfur about 2 feet from the outer edge of the bush's canopy. Scatter the sulfur evenly over the soil approximately 4 to 6 inches away from the hydrangea shoots. This is the area where most of the growing roots are located and take up water and nutrients.
      • Using a small hand rake, stir the elemental sulfur into upper layer soil (1 to 2 inches), then water the area thoroughly to allow the sulfur to soak into the soil. The elemental sulfur will need to be reused from time to time to ensure the flowers retain their blue color.

    2. Use acidic compost and aluminum sulfate powder. If you are planting hydrangea in a garden with alkaline soil and want blue flowers, you will need to amend the soil when planting. sufficient quantity acidic compost and aluminum sulfate and regularly apply these substances throughout the life of the plant.

      Apply a fertilizer low in phosphorus and high in potassium. All hydrangeas benefit from fertilizer. To get or maintain blue hydrangea flowers, use a low-phosphorus, high-potassium fertilizer.

      To increase soil acidity, use organic matter. If you are keeping your garden chemical-free, use organic matter such as grass clippings, fruit and vegetable scraps, or used coffee grounds. Gradually the soil will become more acidic.

      Water hydrangeas with rainwater. Try to use for watering hydrangeas rainwater, not tap water. If you use "solid" tap water for blue hydrangeas, it will neutralize the acidity of the soil and the flowers will gradually turn pink. You can learn how to collect rainwater from this article.

Blue hydrangea - beautiful blooming garden shrub. He looks great in landscape compositions, suitable for decorating hedges, decorating gazebos, paths. Currently, many varieties have been bred that can easily withstand winter and delight with their flowering for many years. A separate type"blue hydrangea" does not exist. The plant received this name for the shade of its flowers. Varieties of large-leaved hydrangea are mainly covered with blue and blue inflorescences. There are two- and three-color species that change their shade throughout the season. Today we will talk about planting and caring for blue hydrangea.

Hydrangea varieties with blue inflorescences

As a rule, these are large-leaved hydrangeas. They are distinguished by rounded inflorescences, long and abundant flowering. Initially, flower growers saw large-leaved hydrangeas in potted varieties. Such crops were not suitable for growing in open ground. They were simply freezing. And only much later were they withdrawn frost-resistant varieties. Which ones have blue flowers?

  1. Hydrangea "Mini Penny". Remontant variety. Blooms on the shoots of the current year. It has lush green foliage and pale blue flowers collected in spherical inflorescences.
  2. "Ramars". A small compact bush. Refers to multi-colored varieties. Some species become covered with purple or purple flowers. Others are striking bright blue and white.
  3. "Freedom". Two-color variety. At the beginning of flowering, pink flowers appear against a background of rich greenery. Then their center turns blue and the edges turn white.
  4. "Compeito." Hybrid variety with large lilac-blue flowers, the middle of which is white.
  5. "Perfection". Rose-like flowers are pink at first. Then the hue changes to blue.
  6. "Hopcorn Blue." A low bush up to sixty to eighty centimeters with tulip-like blue flowers. Blooms on shoots of the second year.
  7. "Jomari." Compact bush with blue double flowers. It also blooms on branches of the second year.

When to plant blue hydrangea

The best time to plant hydrangeas is spring, when the ground thaws and the buds have not yet bloomed, and autumn - in September. When choosing a place for an ornamental foliage plant, keep in mind that it is better to plant hydrangea in the shade or partial shade, since bright sun causes slow growth, as a result of which the inflorescences become smaller.

Preparing the soil for planting blue hydrangea

The soil for hydrangea should be well-drained and moist, consist of a balanced mixture of humus, leaf soil, peat crumbs, river sand(2:2:1:1). Regardless of the type and variety of hydrangea, remember that lime in the soil negatively affects development. The soil should have a Ph level of approximately 5.0. Alkaline soil leads to chlorosis (yellowing of leaves). When a bush grows on alkaline soil, there is often a lack of iron and magnesium, which is manifested by light and pale color of the leaves. Therefore, acidify the soil or treat the bush with iron chelate. In past centuries, gardeners buried objects made of iron (nails, a jar, a horseshoe). When planting, prepare a special balanced soil mixture with fertilizers.

Planting blue hydrangea in open ground

The empty planting hole must be thoroughly flushed with water. The surrounding soil should be saturated with moisture. To do this, pour at least 3 buckets of water into the hole. After a day, you can start planting the plant. For planting, mix the amount of soil substrate required to fill the hole. To the specified soil composition add dry mineral fertilizers(50 g of fertilizer per 1 plant) and mix thoroughly. You can also use specialized fertilizers for hydrangeas. The planting hole is filled with prepared soil substrate, compacting it slightly. In the center, make a hole the size of an earthen ball on the roots of the seedling. The bush is placed in a hole, the roots are buried in soil. The soil around the bush is compacted by hand. If, after compaction, the planting hole is not filled enough, add substrate on top. After planting, the blue hydrangea is watered well so that the entire volume of soil in the hole is saturated with moisture. Following this, the soil is covered with a layer of mulch. It consists of crushed bark or sawdust of deciduous trees. Mulching the soil is necessary to retain moisture in the soil.

When planting several hydrangea bushes, the distance between them should be at least 1 m. This is necessary so that the bushes, as they grow, do not shade each other. If you want to plant hydrangea in a row, then you can dig a trench 90-110 cm wide. If you want to achieve earlier flowering, then when planting, dig holes closer to each other (70-80 cm), and after 2-3 years, thin out the bushes at necessary. Planting pit Depth - 36-45, width - 51-65 cm. The roots grow mainly in breadth, extending much further than the crown. Planting depth The root collar should be located at soil level, a maximum of 2-3 cm lower, otherwise the flower will develop poorly. Now that you know how to plant hydrangea correctly, you need to care for the plant in a timely manner.

Blue hydrangea care

Caring for hydrangea consists of weeding and loosening the soil around it, organizing a timely and correct watering regime. In addition, to prevent rapid evaporation of moisture, it is recommended to mulch the bush at the beginning of summer with peat or sawdust.

In the fall, plants are fed with complex fertilizers, and in the spring with urea (2 tablespoons per adult bush, diluted in 2 buckets of water and watered). This allows them to develop and form large panicles.

During the growing season, the plant can be fertilized with slurry, but if you overdo it organic fertilizers, then the branches of the bush may break off under the weight of the inflorescences.

Pruning blue hydrangea

It is important to form the bush correctly. Gardeners do not like to prune branches, but in the case of paniculata hydrangea, without heavy pruning, you can not wait abundant flowering.

Trimming rules:

  1. In autumn, all inflorescences are cut off.
  2. In the spring, all weak and frozen branches growing inside the bush are cut out into a ring.
  3. In the spring, the annual growth is shortened, leaving no more than five pairs of buds on each.

This pruning helps the bush bloom more luxuriantly every year. What does “abundant flowering” mean in the case of paniculata hydrangea? Five year old specimen good care will please the owner with several dozen panicles, and a twelve-year-old with several hundred! The plant lives in the garden for 50 years or more. A specimen older than 20 years can be rejuvenated by cutting the bush to a stump. But even such pruning will not prevent the plant from blooming in the same year.

Protecting blue hydrangea from pests

Blue hydrangea is affected only by aphids and red spider mite. These pests feed on plant sap and are able to reproduce in large numbers. Very often, the lack of control against them leads to the death of the plant.

  • Leaf aphids accumulate on the tips of shoots and petioles of the youngest leaves. Gradually multiplying, it sucks out the sap of the plant, which leads to curling and drying of the tops of the shoots. Only purchased ones can help in the fight against them. insecticidal preparations to destroy aphids.
  • Spider mites are classified as harmful arachnids. Ticks are very small and often invisible to the naked eye. You can only notice the web on the youngest leaves of the plant. To combat this dangerous pest There are drugs - acaricides and insecto-acaricides that destroy harmful arachnids.

    • How to grow blue hydrangea

When grown and cared for at home, indoor hydrangea is a semi-shrub spreading plant, reaching a meter in height, with large oval leaves (10-15 cm long) with jagged edges. Large inflorescences (about 35 cm in length) are umbrella-shaped and consist of sterile small flowers at the edges and fruit bearings in the central part.

The color palette can be adjusted using the soil: more acidic soil colors the flowers blue, neutral soil gives them a white or beige color, and alkaline soil gives them a lilac or pink color. The hydrangea fruit is a capsule with a large number of seeds.


Types and varieties of indoor hydrangea

White and cream hydrangeas

  • Hydrangea Mme E. Mouillere – inflorescence diameter up to 20 cm, flowers from 1-5 cm, leaves narrow.

  • – flowers correct form, inflorescence diameter up to 20 cm, bush height – 35-40 cm. Blooms early.

Hydrangeas Pink

  • - a bush, up to 70 cm high, the inflorescences are quite large (30 cm) of a dark pink hue, the edges of the sepals are deeply cut. Starts to bloom late.

  • - It has small flowers(up to 5 cm) pink, collected in an inflorescence with a diameter of 16-18 cm. The bush reaches a height of 40 cm.

  • – the bush reaches a height of 50 cm, blooms large flowers(up to 6 cm) in inflorescences with a diameter of about 25 cm. Has abundant flowering.

Red hydrangeas

  • – burgundy-red inflorescences. It is possible to obtain a purple-burgundy color if you add iron salts or aluminum sulfate to the soil.

  • – the diameter of the inflorescences is up to 18 cm, while the flowers themselves are small – no more than 3.5 cm, the height of the stem is 20-25 cm.

Blue hydrangeas

  • - a tall bush with bright blue inflorescences.

  • – This variety is distinguished by its compactness. Inflorescences with a diameter of up to 20 cm have a peculiarity: over time, the tips of the petals turn green.

Indoor hydrangea care at home

For hydrangeas, the correct temperature regime. On the hottest days of summer, the temperature should not exceed 20°C, and in winter, not lower than 10°C.

Indoor hydrangea does not like direct hits sun rays, so the most comfortable place will be the south side of the apartment, at a distance of 1-2 meters from the window.

If you have garden variety, then you can familiarize yourself with the rules for planting and caring for hydrangeas in the open ground.

Watering hydrangea

In summer, frequent and abundant watering is required, in spring and summer it is reduced, and in winter it is practically eliminated (just moisten the soil a little, avoiding drying out).

Water for irrigation must be settled or frozen (thawed), room temperature. In addition, we must not forget about regular moisturizing air. Spray with a spray bottle.

Fertilizer for hydrangeas

Fertilizers are added once every two weeks during periods of active growth (the appearance of new shoots) and flowering. Mineral fertilizers are suitable for flowering indoor plants.

Hydrangea changes color

Indoor hydrangea has one more unusual feature, but actually the opportunity to make a colored bush.

This is done using different composition substrate, for example, adding a solution of ammonia-potassium alum (4-5/l) or iron salts will color the inflorescences blue, lime gives a pink or purple color, and white or cream flowers usually grow in neutral soil. Thus, you can make a colorful bush by adding different fertilizers to different parts of the pot.

Hydrangea transplant

The indoor beauty is replanted every year, increasing the size of the pot by a couple of centimeters. Replanting should be done with caution.

Place drainage at the bottom of the new pot, sprinkle a little new soil, then carefully remove the flower from the old pot, along with all the soil, and place it in a new place of residence.

Fill the voids with fresh substrate and water. After which a layer of peat is laid on top for mulching (slows down the rate of moisture evaporation).

Do I need to prune hydrangeas for the winter?

Pruning hydrangeas is required. It is held twice a year.

  • The first, after the end of flowering, before wintering, when weak, withered shoots are cut to the ground, and strong ones - by half.
  • The second time, in the spring, when new shoots become very long, they are shortened so as not to weigh down the plant.

Hydrangea preparing for winter

The hibernation period for hydrangeas begins after flowering ends. At this time, it must be removed to a darker and cooler place.

Having fulfilled this condition, the flower will have time to rest and gain strength after abundant flowering, and already in February the buds will begin to wake up (the plant can be returned to its usual place). Otherwise, the next flowering will not occur earlier than in a year.

Propagation of hydrangea by cuttings in the fall at home

Cuttings are the most reliable way reproduction. If you carry out this procedure in January-February, then by next autumn there will be a real bush of 3-4 shoots, and if later, the plant will put out only one stem. Cuttings with at least three internodes are cut from the root shoots. Lower leaves are torn off, and the top ones are cut by half (for large leaves) or by a third (for small ones).

A shoot approximately 8 cm long, placed in a prepared substrate of peat and sand, watered and covered glass jar or a cut plastic bottle to provide moisture. Ventilate every day and do not allow the soil to dry out. After about a month, the plant takes root and can be transplanted into a separate pot; for starters, 8-9 cm in diameter will be enough.

Dividing a hydrangea bush

The easiest way to divide a hydrangea bush. This procedure is carried out during the annual transplant.

To do this, the bush is carefully removed from the pot and divided into parts (the number of parts depends on the density of the rhizome), so that each has a sufficient number of roots and shoots. In each divided area, the roots and shoots are shortened and placed in new pots with prepared soil.

Hydrangea from seeds at home

Hydrangea seeds are sown at the end of winter, on a substrate previously prepared and poured into seedling boxes: a mixture of leaf, turf land, humus, sand and peat (1:1:1:0.5:0.5). There is no need to sprinkle soil on top.

Moisten and cover with glass or film. Ventilate every day and moisten as necessary. With the emergence of seedlings, the glass (film) is removed and the seedlings are thinned out. As soon as leaves (2-3) appear on the young shoots, they are transplanted into separate pots (7-8 cm in diameter) with the same soil.

Diseases and pests

  • Gray rot – affects the plant when too high humidity. Treatment: treatment with Bordeaux mixture.
  • Spider mites and aphids – affects the bush with insufficient humidity. Treatment: wipe leaves and shoots soap solution with a sponge, if it doesn’t help, then treat it with Actellik after a week.
  • The leaves are turning yellow – insufficient watering, lack of nitrogen in the soil or the soil is too alkaline, which causes chlorosis. To restore their strength and color, add inkstone(10 g/l) or ferrous sulfate (2 g/l).
  • Indoor hydrangea begins to dry out (tips dry) - due to insufficient moisture and watering, as well as lack of fertilizers. Correct the defects, otherwise next consequence leaves and buds will fall off. So remember to water, spray and fertilize as needed. Follow the plant, it will tell you.
  • Indoor hydrangea does not bloom - this is a consequence of the fact that the plant did not rest in winter, but continued to grow and bloom, spending a lot of energy. At the end of autumn, the bush must be pruned and placed in a cool, dark place for wintering. And in the spring, take it back and continue caring, then the hydrangea will definitely bloom again.
  • Appear brown spots on the leaves - lack of watering.
  • Light spots on leaves - excess light. Move the flower into the shade. Hydrangea is afraid of direct sunlight.
  • Slow flower growth – an insufficient amount fertilizers Worth feeding.

Do you want your garden to smell fragrant and make you happy? long flowering? Then you need to place the recognized garden beauty Hortensia there, named after the princess of the Roman Empire. This perennial shrub will delight you from July to September with its spherical inflorescences, which first have a greenish tint, then at the very peak of flowering turning into a bright white color, turning slightly yellow in the fall. And if you plant large-leaved, or garden, hydrangea, you can achieve pinkish or bluish shades. Let's try to figure out how to change the color of garden hydrangea.

In nature, there are several dozen varieties of hydrangea. However, only

Garden hydrangea is the only type of hydrangea whose flowers can be changed from white to blue or pink

Garden, or large-leaved, hydrangea is the most popular and widespread type of plant, which is ornamental shrub. The scientific name of hydrangea (Hydrangea macrophylla), translated as “water vessel”, is explained by the increased moisture-loving nature of the flower. Hydrangea has large leaves egg-shaped with pointed edges. The shrub blooms with lush spherical voluminous inflorescences. The most common colors are white or pink. There are also lilac and blue inflorescences.

The color of the spherical inflorescences depends on the acidity of the soil. By the color of the hydrangea, you can determine the acid-base environment of the soil: pink color indicates slightly alkaline or neutral acidity, blue indicates increased soil pH.

So change the color garden hydrangea possible by increasing/decreasing soil acidity. It is better to take care of this before planting the bush. To do this, you need to decide in advance on a place in the garden, prepare the appropriate substrate, plant the plant and monitor the acidity level of the soil.

How to test the soil

Any gardener, even an amateur, knows that good harvest largely depends on knowledge chemical composition the soil of your site. One of important indicators is the acidity, or pH, of the soil.

Soil acidity is a quantitative indicator of the content of acids and salts. The pH value is determined by values ​​from 0 to 14.

In relation to the earthen mixture, they mean the following

up to 4 – strongly acidic environment;

from 4.5 to 5.5 – acidic soil;

from 5.5 to 6.5 – slightly acidic soil;

from 6, 5 to 7 – neutral land;

above 7 – alkaline environment.

How to determine soil acidity yourself

Soil acidity is determined very accurately with a special device, but approximate values ​​can be measured independently.

We offer you several simple and available ways determination of soil pH:

  • Vinegar essence.

It is enough to pour a few drops of vinegar onto a handful of soil and observe the reaction. If violent boiling occurs, accompanied by the release of carbon dioxide, which means you have an alkaline environment. Small bubbles and weak soil reaction indicate neutral acidity. The absence of any reaction indicates that the soil is acidic.

  • Grape juice.

Place a pinch of soil in a vessel with grape juice. A change in the color of the drink and the appearance of gas bubbles indicate normal soil pH.

  • Currant or cherry leaves.

Pour boiling distilled water over a few leaves. Cool the liquid and throw a handful of earth into it. The change in color of water after some time is an indicator of acidity: red water is acidic, blue is slightly acidic, green is neutral soil.

  • Litmus paper.

Place some soil on a clean piece of fabric. Tie it tightly into a knot and dip it in distilled water. Wait until the water is well absorbed into the soil. Lower the litmus paper. A change in color will allow you to draw a conclusion about the condition of the soil: from yellow to red - an acidic environment, blue-blue shades - neutral soil. This is one of the most reliable methods. Litmus paper is freely available in agricultural stores.

Most in a simple way Determining the soil pH level is visual. If, upon careful examination of the soil, you see reddish-rusty shades, then the soil is highly acidic. A thin iridescent film on water accumulated after watering or rain is evidence of an acidic soil environment.

Video “How to determine soil acidity and ways to deoxidize it”

Changing the color of the queen of the garden

Knowing the acidity of the soil on your own garden plot, you can achieve the desired color of hydrangea. Acidic soil with a pH level below 7 will allow you to grow a blue, moisture-loving beauty. An alkaline environment (acidity above 7) is good for pink hydrangea. pH values ​​of 5.5 – 6.5 will produce shades or a pink-blue mixture.

However, knowing the pH value of the soil and choosing a specific type of shrub is not enough. An important factor is the presence of aluminum in the soil. When the acidity is above 6.5 (neutral and alkaline), aluminum is not available to the plant, so the hydrangea will produce pink flowers.

Blue hydrangea needs acidic soil to help dissolve aluminum. In this case, the presence of aluminum is more important for the flower than the pH level of the soil. In addition, the availability of the element is influenced by the nutrients contained in the soil.

In general, the color of hydrangea is influenced by the type of shrub, the level of soil acidity, aluminum and the fertilizers used.

After planting, hydrangea, adapting to a new environment, can change color on its own. And in a year, the queen of the garden can please you with several shades on one shrub at once.

To control the color of the shrub, it is necessary to regulate the pH level of the soil. This begs the question of what to water with to change the color of the queen of the garden.

There are special agricultural techniques, helping to achieve a change in shades of inflorescences, which are best used on early stage bush growth. Let's take a closer look at them.

Pink hydrangea

Changing the color of garden hydrangea from white to pink

To change the color of hydrangea from white to pink, you need to maintain a pH above 6.5. If the acidity of the soil in your area is such, hydrangea will throw out pink inflorescences. In this case, there is no need to take additional measures.

Acidic soil should be fertilized several times a year with chalk, limestone or dolomite flour. However, do not overdo it: it is enough to achieve acidity levels of 6-6.2. If values ​​exceed these values, soil chlorosis or iron deficiency may occur.

To provide the soil with essential nutrients, feed the soil with fertilizers that contain high concentrations of nitrogen and phosphorus but low concentrations of potassium. Aluminum in combination with phosphorus forms insoluble compounds, which will prevent the appearance of blue inflorescences. Choose N:P:K fertilizer in a ratio close to 25:10:10. Ammonium monophosphate works great.

If the environment in your area is too acidic, then professional gardeners recommend planting hydrangea in large pots, using a peat substrate with a small amount of aluminum salts as soil. In this case, the universal substrate sold in special stores is recognized as the best. This will make growing and caring for the pink large-leaved garden queen much easier.

Blue moisture-loving beauty

Changing the color of hydrangea to blue

To change the shade of the inflorescences to blue, it is necessary to maintain an acidic environment (below 5.5 pH) containing a soluble form of aluminum available to hydrangea.

If your garden is dominated by acidic soil with a sufficient concentration of aluminum, then the hydrangea will independently fulfill your wish by producing blue caps.

You can increase the acidity of the soil by specially acidifying the root zone. To do this, it is enough to add high-moor peat or sulfur used in planting to the planting hole. agriculture. Then it is enough to regularly water with aluminum sulfate in a proportion of 15 g per liter. Make sure that the soil is moistened before watering with a special solution.

To change the color of a previously planted hydrangea, add high-moor peat or the bark of coniferous trees to the soil near the bush.

The change in shade can be affected by feeding with complex fertilizers containing potassium (high concentration), phosphorus (low percentage), nitrogen (average value). The ideal ratio would be N: P: K, close to 10:5:20. Do not use bone meal or superphosphate.

It is allowed to grow blue hydrangeas in large containers using ready-made substrates. Professionals advise choosing an acidic substrate for coniferous plants.

Video “How to change the color of hydrangea to blue”

By following the above recommendations, you will definitely get the desired result. However, don't expect your hydrangea to change color instantly. This period can take from several months to a year depending on weather conditions, quality of fertilizers and other factors.

Hydrangea is one of the most beautiful flowering bushes. Lush spherical inflorescences, behind which the foliage is almost invisible, cannot but attract admiring glances. And thanks to the relative non-capriciousness of hydrangeas, they will decorate even an unkempt garden.

By the color of hydrangea inflorescences, you can determine the acid-base reaction of the soil in which it grows. Plants will bloom on soils with a slightly alkaline and neutral reaction. pink flowers, on acidic soils - blue and even blue. And if you take care in advance to prepare the appropriate substrate and choose right place for planting shrubs, you can get the desired color of the flowers. But in fact, the color of hydrangea flowers depends not only on the variety and pH of the soil. These plants require aluminum to produce the blue pigment. So the key factor in changing the color of the inflorescences is the presence of aluminum in the substrate. Majority garden soils have a sufficient amount of aluminum, but it will not be available to plants if the soil pH is high (above 5.5). Aluminum compounds present in the soil in an acidic environment are converted into soluble forms accessible to plants. The aluminum is absorbed by the bush, resulting in a blue flower. In neutral or alkaline soil, aluminum remains bound into insoluble compounds that are inaccessible to plants. The result is natural pink flowers. Thus, to obtain hydrangea with blue inflorescences, you need two of the most important factors– acidic substrate and aluminum salts (usually aluminum sulfate).

There is one more nuance - phosphorus easily binds aluminum into poorly soluble compounds that are inaccessible to hydrangeas. To ensure sufficient free aluminum for flowers, phosphorus levels must be kept to a minimum.

To get a rich blue tint, you need to do the following:

Measure the pH of the soil, it should be between 5.0 - 5.5. Only with such indicators will aluminum salts become available to hydrangea. More high values pH will result in transitional colors with shades of purple. If the soil in the garden is neutral or alkaline, it is necessary to artificially acidify it in the root zone to a depth of 20-30 cm or replace the soil in the planting hole with previously prepared acidic soil. Non-carbonate soil can be acidified to pH 5.0-5.5 with high-moor peat or agricultural elemental sulfur before planting hydrangeas. Subsequently, the low pH is maintained by regularly watering the plant with a solution (15 g/l) of aluminum sulfate throughout the entire growing season. Do not water dry soil; first moisten it well with clean water.

Buy aluminum sulfate or potassium alum. It is recommended to add dry aluminum sulfate in the following proportions: per 1 m² up to 0.5 kg of dry aluminum sulfate. Or dissolve alum or aluminum sulfate in water and water the bushes once every one to two weeks, but not less often. At the same time, observe the proportions: take 30 - 40 g of sulfate or alum per bucket of water. The norm for one adult bush is two to three buckets. Otherwise, the color will change partially.

To increase acidity, mulch the soil near the hydrangea with acidic materials - high peat, coniferous bark. Do not use marble chips, expanded clay. Can be applied diluted under the bush Apple vinegar, sawdust, chopped grass.

The applied fertilizer also affects the color change. Fertilize with acidic complex fertilizers with low phosphorus content, high potassium content and medium nitrogen level, N:P:K ratio close to 10:5:20. Avoid superphosphate and bone meal, which are sometimes used to promote fuller blooms.

It's important to know that too a large number of added alum can cause root death, so do not try to quick effect and follow the rules when diluting the solution.

The pink color of hydrangea appears as the acidity of the soil decreases.

Hydrangeas will produce pink flowers if they cannot produce the blue pigment that requires aluminum. This means that the aluminum in the soil must be converted into a form inaccessible to plants. For this, the soil pH must be above 6.0. If the value is above 6.5, the plant may suffer due to lack of nutrients. There is no need to strive for the soil to be truly alkaline; this is harmful to the plant itself. In alkaline soils, hydrangeas will be deficient in iron and magnesium, without which the formation of chlorophyll in the leaves is impossible. This manifests itself as interveinal chlorosis.

Add dolomite flour, chalk, fluff lime, or ground limestone to raise the soil pH to 6.0-6.5. If the acidity is too high, they need to be applied several times a year.

To maintain an intense pink color, feed the bushes with fertilizers with a sufficiently high content of nitrogen and phosphorus, but low level potassium Phosphorus forms insoluble compounds with aluminum chemical compounds, and the metal is not absorbed by the plant. Select a fertilizer type with an N:P:K ratio close to 25:10:10. Monoammonium phosphate (11:53:00) can be used.

In some cases, the soil throughout the entire area is very acidic, then it is more convenient to grow pink hydrangea in separate pots or containers, pouring soilless substrates, such as peat, into them. There are practically no aluminum compounds in peat. It is much easier to maintain in such containers necessary for the plant mode.

Plants that require acidic soil (rhododendrons, azaleas) should not be grown next to pink hydrangea.

Once your hydrangeas have turned blue or pink, adding more amendments to the soil will not help enhance the depth of color. Color may vary from season to season due to weather conditions, plant stress, and environment. For example, plants planted near concrete foundation or concrete path may never turn blue due to the lime that leaches from the concrete.

It should be borne in mind that the color of hydrangea changes as the plant develops and matures, so if you plant, for example, pink hydrangea in acidic soil, you will be able to see blue inflorescences only after a few years.